﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo12
{
    class Program
    {
        static void Main(string[] args)
        {
            //圆形的面积
            Circle c = new Circle();
            c.Radius = 5;
            c.GetArea();
            //正方形的面积
            Square s = new Square();
            s.SideLen = 5;
            s.GetArea();
            Console.ReadKey();
        }
    }
}
